It's been a long first quarter of school. Stormy, Cassie, and Gabriella are looking forward to enjoying a two week long camp excursion. With crisp fall weather already coming to northern Arizona, the girls feel Halloween is on its way. They even meet three new friends.An afternoon hike to the Shrieking Cavern is the first thing to give them spooky chills. A haunted cry sends them fleeing back to camp. Later that night at the bon fire, one of the camp counselors tells a chilling tale of Aztec gold, treachery, and one lost soul. A miner is said to haunt the Shrieking Cavern, warning away anyone who would try to steal Montezuma's treasure.Soon, the girls discover that one of their new friends has gone missing. She was last thought to have gone to the Shrieking Cavern by herself. One by one, three more campers vanish. Their only connection is they have all hiked to the cavern.The girls are hot on the trail of an Aztec warrior ghost. The only question is how do you catch a ghost?